platform/x86/fujitsu-laptop: Replace sprintf() with sysfs_emit()

platform/x86/fujitsu-laptop: Replace sprintf() with sysfs_emit()

As suggested by Documentation/filesystems/sysfs.rst sysfs_emit() should be
used when formatting the value to be returned to user space.

Signed-off-by: Szilard Fabian <szfabian@bluemarch.art>
Link: https://lore.kernel.org/r/20240428192548.113261-1-szfabian@bluemarch.art
Acked-by: Jonathan Woithe <jwoithe@just42.net>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>